1. A car travels 45 kilometers/hour and accelerates to a speed of 65

oksano4ka [1.4K]

<h2>Answers:</h2>

<h2>1. event horizon </h2>

The event horizon is the surface of a black hole, it is the border of space-time in which the events on one side of it can not affect an observer on the other side.

That is, at this border also called <em>"point of no return"</em>, nothing can escape (not even light) and no event that occurs within it can be seen from outside.

<h2>2. gravitational lensing </h2>

According to Einstein's theory of relativity, mass causes the curvature of spacetime and this curvature is what we call <u>gravity</u>.

Then, the light always move following the curvature that gravity causes in spacetime, and in this way the rays of light are deflected if there is a mass accumulation nearby. Being this is the principle of the gravitational lensing.

<h2>3. black hole </h2>

According to Einstein's theory of relativity, inside a black hole there is a <em>"singularity"</em> that consists of a region of the space in which <u>the density of matter tends to infinity. </u>

How is it possible?

Following what relativity establishes, bodies within a gravitational field follow a curved space path. Then the more a body enters the black hole, the more curved the space will become, until, in the center, it will become infinitely curved.

<h2>4. gravitational waves </h2>

Gravitational waves were discovered (theoretically) by Albert Einstein in 1916 and "observed" for the first time in direct form in 2015.

These gravitational waves are fluctuations or disturbances of space-time produced by a massive accelerated body, modifying the distances and the dimensions of objects in an imperceptible way.

In this context, an excellent example is the system of two neutron stars that orbit high speeds, producing a deformation that propagates like a wave, <u>in the same way as when a stone is thrown into the water. </u>

<h2>5. wormhole</h2>

A wormhole is <u>a hypothetical feature of a space-time</u> described in the equations of general relativity, which essentially consists of a shortcut through space and time. It is not proven that they exist, although <u>mathematically they are possible</u> .

In other words:

A wormhole is a tunnel that joins two black holes in different places (two points of spacetime).

<h2>6. time dilation (gravitational) </h2>

The dilation of time is a phenomenon that results from the theory of relativity, which states that time passes at different rates in regions of different gravitational potential.

That is, the greater the local distortion of spacetime due to gravity, the slower the time passes.

<h2>7. gravitational redshift</h2><h2 />

When we talk about the <u>visible electromagnetic spectrum</u>, we know it starts in violet-blue and ends in red.

Now, in this context the astronomer Edwin Powell Hubble observed several celestial bodies, and when obtaining the spectra of distant galaxies he observed that the spectral lines were displaced towards the red one (red shift), whereas the nearby stars showed a spectrum displaced to the blue one.

From there, it was deduced that the farther an body in the universe is, the more redshifted it is in its spectrum. This effect is due to the dilation and contraction of time by speed.

7 0

3 years ago

__________ explains what happens in an event and __________ applies knowledge to create something or change an existing process.

Yuliya22 [10]

An hypothesis is a sort of "untested idea" as to what might be happening. I guess it becomes a theory if experiments back it up, and if the combination leads to other things.So, I'd go for The top pair of answers.

3 0

3 years ago

Standing waves can be established within a cylindrical volume. However, it is not known if the volume is closed at both ends, op

Evgen [1.6K]

The frequencies are missing in the question. The three successive resonance frequencies within the volume are $f_1, f_2 \text{ and}\ f_3$ .

Solution :

Let the volume be : v

The frequency for one end open and one end closed is given by :

So, $f_n = \frac{(2n-1)v}{4L}$

Therefore,

$f_1 = \frac{v}{4L}$ , $f_2 = \frac{3v}{4L}$ , $f_3 = \frac{5v}{4L}$

So, $f_2 - 3f_1$ and $f_3=\frac{5}{3}f_2$

Therefore, the ratio of $\frac{f_3}{f_2}=\frac{5}{3}$ which is not a whole number.

Now the frequency for open volume and closed at both end

$f_n=\frac{nv}{4L}$

So, $f_1=\frac{v}{4L}$ , $f_2 = 2f_1$ , $f_2=3f_1$

From above formulae we can see that ratio of is not a whole number that is a identification for the frequency of the volume at one end open and one end closed.

Also ratio of the consecutive frequency of the volume at open from both side and closed from both side is always a whole number.

4 0

3 years ago

11. Reflecting telescopes are popular because they're _______ than a refracting telescope.

Anon25 [30]

I do not know what the school expects as an answer, but advantage of reflecting telescopes is that there is only one major reflecting surface, so it is quite easy to create a 6 or 8 inch telescope by an amateur, after adding on a prism and an eyepiece. (a microscope eyepiece could be used).
MY answer would be "easier to build". (it still takes tens of hours to grind and polish the single plane surface to a parabolic surface).

Electromagnetic waves all have the same velocity in the same medium. However, since frequencies vary widely, so do wavelengths.

4 0

3 years ago

Read 2 more answers

A transformer has 1000 turns in the primary coil and 100 turns in the secondary coil. If the primary coil is connected to a 120

Marianna [84]

Answer:

The voltage on the secondary is 12 V while the current is 0.5 A.

Explanation:

A transformer works by changing the level of the voltage and current on a circuit using a magnetic field and two coils. The ratio by wich they are changed is dependant on the ratio of turns between the primary and secondary of the transformer. In this case we have a ratio for the voltage of:

ratio = (turns on the secondary)/(turns on the primary)

ratio = 100/1000 = 0.1

So in this case the voltage delivered to the primary will be multiplied by 0.1. We can now calculate the voltage on the secondary:

Voltage secondary = Voltage primary* ratio = 120*0.1 = 12 V

The transformer maintains roughly the same power output on both sides, since the power output on a electric circuit is given by the product of the voltage by the current on that circuit, to maintain the same power when the voltage has been droped the current must be raised by the same ratio. So we have:

Current secondary = Current primary*(1/ratio) =0.05*(1/0.1) = 0.5 A

6 0

3 years ago